Two undercover agents, we’ve learned, slipped into a mixer for Harvard graduates and their guests last April, and one was served a glass of wine. That was an alleged violation of a law that prohibits clubs from pouring alcohol for anyone but “bona fide members of the club and their bona fide guests.”

In a Feb. 22 letter to the Department of Alcoholic Beverage Control, or ABC, an attorney for the club ripped the operation. He compared it to the infamous tale of Tareq and Michaele Salahi, who “Salahied” their way into a state dinner at the White House.

“Showing up at an event like this and acting as an invited guest,” wrote lawyer John Hinman, “is called ‘crashing.’ Can an event be crashed? Certainly, but it requires guile and deception.”

The ABC stands by the operation and its decision to seek a 10-day liquor license suspension — which would be the first in the club’s 120-year history.

A spokesman said the agents visited the University Club’s stately brick headquarters across from the Fairmont after receiving a complaint that the organization was serving alcohol to members of the general public.

The agency declined to give further details, but case documents provide the following account: The investigators, after learning of the April 24 mixer through a simple search on Google, showed up and filled out name tags at a registration table. In an effort to fit in with other guests, one agent wrote, “Bob, Stanford” — even though, yes, he was a Cal grad.

Then came the fateful glass of wine, and, a month later, a formal accusation against the club.

The club fought the charge, sending the case to an October hearing in front of an administrative law judge. Hinman said the judge “found liability but declined to impose discipline.”

The ABC, though, is not required to follow the judge’s lead, and expects to render a final decision sometime next month.